Luminescent material

ABSTRACT

A luminescent material is disclosed. The luminescent material may include a first compound having a host lattice comprising first ions and oxygen. A first portion of the first ions may be substituted by copper ions. In one embodiment, the host lattice may include silicon, the copper ions may be divalent copper ions and the first compound may have an Olivin crystal structure, a β-K 2 SO 4  crystal structure, a trigonal Glaserite (K 3 Na(SO 4 ) 2 ) or monoclinic Merwinite crystal structure, a tetragonal Ackermanite crystal structure, a tetragonal crystal structure or an orthorhombic crystal structure. In another embodiment, the copper ions do not act as luminescent ions upon excitation with the ultraviolet or visible light.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/024,722, filed on Dec. 30, 2004, the disclosure of which isincorporated by reference herein in its entirety, which claims priorityto Korean Patent Application No. 2004-042397, filed Jun. 10, 2004, thedisclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

1. Field of Invention

Embodiments of the present invention relate generally to fluorescentmaterials containing rare earth elements and, more particularly, to suchluminescent materials for exciting ultraviolet as well as visible lightcontaining lead- and/or copper-containing compounds.

2. Description of the Related Art

Lead and copper activated materials are known for short wave excitation,e.g. from a low pressure mercury lamp, such as barium disilicateactivated by lead (Keith H. Butler, The Pennsylvania State UniversityPress, 1980, S 175, orthosilicate activated by lead (Keith H. Butler,The Pennsylvania State University Press, 1980, S. 181), akermanitesactivated by lead, or Ca-metasilicate activated by Pb²⁺.

Generally, the maxima of the emission bands of such lead activatedphosphors are located between 290 nm and 370 nm at 254 nm excitation.Bariumdisilicate activated by lead is an U.V. emitting phosphor whichcurrently is used in sun parlor lamps.

Lead has in the ground state ¹S₀ two outer electrons. The electronconfiguration of the ground state is d¹⁰s², so that the lowest excitedstate has d¹⁰sp configuration. The excited sp configuration has fourlevels, ³P₀, ³ P₁, ³P₂ and ¹P₁, which can be achieved between 165.57 nm(³P₀) and 104.88 nm (¹P₁) in the free ion. Transitions between ¹S₀ and¹P₁ excited level are allowed by all selection rules. While transitionsbetween ¹S₀ and ³P₀ are only allowed with the lowest symmetry,transitions between ¹S₀ and ³P₁ as well as ³P₂ are allowed only undercertain conditions. However, excitation between 180 and 370 nm has thesame emission. Excitation with wavelength longer than 370 nm is notpossible.

Otherwise, luminescent materials are known having lead as a host latticecomponent. Molybdate phosphors containing MoO₄ ²⁻-centers are describedin Bernhardt, H. J., Phys. Stat. Sol. (a), 91,643, 1985. PbMoO₄ shows atroom temperature red emission with an emission maximum at 620 nm underphotoexcitation at 360 nm.

However, such emission is not caused by lead itself. In molybdates theluminescence properties are not caused by the metal ion M²⁺ (M²⁺MoO₄where M²⁺=Ca, Sr, Cd, Zn, Ba, Pb etc). Here, defect centers of MoO₄ ²⁻ions coupled to O²⁻-ion vacancies seem to be the reason. Nevertheless,the Pb²⁺-ion influences the preferred emission properties because itstabilizes the host lattice.

As a familiar example, tungstates (Ca,Pb)WO₄ as mixed crystals have astrong green emission with high quantum output of 75% (Blasse, G.,Radiationless processes in luminescent materials, in RadiationlessProcesses, DiBartolo, B., Ed. Plenum Press, New York, 1980, 287). Under250 nm excitation PbWO₄ shows blue emission and under 313 nm excitationPbWO₄ has an orange emission band, which can be caused by Schottkydefects or by impurity ions (Phosphor Handbook, edited under the Auspiceof Phosphor Research Society, CRC Press New York, 1998, S 205).

Copper was used as a monovalent activator in orthophosphates (Wanmaker,W. L. and Bakker, C., J. Electrochem. Soc., 106, 1027, 1959) with anemission maximum at 490 nm. The ground state of monovalent copper is afilled shell 3d¹⁰. That is the level ¹S₀. After exciting the lowestexcited configuration is 3d⁹4s. This configuration has two terms, ³D and¹D. The next higher configuration, 3d⁹4p, gives 6 terms ³P^(o), ³F^(o),³D^(o), ¹F^(o), ¹D^(o) and ¹P^(o). The transitions between the groundstate ¹S₀ and the ¹D or ³D are forbidden by parity or spin,respectively. In copper ions, the excitation to the crystal field levelsof 4p terms is allowed. Emission will be got either by a direct returnfrom the crystal field odd state to the ground state or by a combinationof transitions first from the odd state to a crystal field level andafter that a second transition from these ³D or ¹D state of the 3d⁹4sconfiguration to the ground state.

The ground state of bivalent copper has 3d⁹-configuration. That is thelevel ²D_(5/2). In the bivalent copper, one of the d-electrons can beexcited to the 4s or 4p orbital. The lowest exciting configuration isthe 3d⁸4s with two quartet terms ⁴F, ⁴P and four doublet terms, ²F, ²D,²P and ²G without emission caused by forbidden transitions. The higherexciting configuration is the 3d⁸4p-configuration with four terms⁴D^(o), ⁴G^(o), ⁴F^(o), and ⁴P^(o), where emission can occur.

Copper activated or co-activated sulphide-phosphors are well known andthey are commercial used for cathode ray tubes. The green-emittingZnS:Cu, Al (wherein, the copper is used as activator and Al is used asco-activator) is very important in CRT applications.

In zinc-sulphide phosphors, the luminescent materials can be classifiedinto five kinds, depending on the relative ratio of the concentration ofactivators and co-activators (van Gool, W., Philips Res. Rept. Suppl.,3, 1, 1961). Here, the luminescent centers are formed from deep donorsor deep acceptors, or by their association at the nearest-neighbor sites(Phosphor Handbook, edited under the Auspice of Phosphor ResearchSociety, CRC Press New York, 1998, S. 238).

Orthophosphates activated by copper (Wanmaker, W. L., and Spier, H. L.,JECS 109 (1962), 109), and pyrophosphates, alumosilicates, silicates,and tripolyphosphates all activated by copper are described in “Keith H.Butler, The Pennsylvania State University Press, 1980, S. 281”. However,such phosphors can only be used for a short wave U.V. excitation.Because of their unstable chemical properties and their temperaturebehavior, they cannot be used in fluorescent lamps.

It has been observed that conventional luminescent materials aregenerally unstable in water, air humidity, water steam and polarsolvents.

SUMMARY

One embodiment exemplarily described herein can be generallycharacterized as a luminescent material for a light emitting diode (LED)that includes a first compound including a host lattice and aluminescent ion within the host lattice. The host lattice may includefirst ions and oxygen. A first portion of the first ions may besubstituted by divalent copper ions. The first compound may emit lightupon excitation with ultraviolet light or visible light emitted by theLED. The first compound may have an Olivin crystal structure, a β-K₂SO₄crystal structure, a trigonal Glaserite (K₃Na(SO₄)₂) or monoclinicMerwinite crystal structure, a tetragonal Ackermanite crystal structure,a tetragonal crystal structure or an orthorhombic crystal structure.

Another embodiment exemplarily described herein can be generallycharacterized as a luminescent material for a light emitting diode (LED)that includes a first compound including a host lattice and aluminescent ion within the host lattice. The host lattice may includefirst ions and oxygen. A first portion of the first ions may besubstituted by copper ions. The first compound may emit light uponexcitation with ultraviolet light or visible light emitted by the LED.However, the copper ions do not act as luminescent ions upon excitationwith the ultraviolet light or visible light.

DETAILED DESCRIPTION

According to embodiments exemplarily described herein, a luminescentmaterial may include one or more lead- and/or copper-containing chemicalcompounds. The luminescent material may be excited by UV and/or visible(e.g., blue) light. In some embodiments, the lead- and/orcopper-containing chemical compounds may be generally characterized asincluding a host lattice having anions and cations. In some embodiments,at least a portion of the cations are divalent cations. In someembodiments, the divalent cations include alkaline earth ions. In someembodiments, at least a portion of the divalent cations of the hostlattice are substituted by divalent lead and/or divalent copper ions.

As mentioned above, conventional luminescent materials are generallyunstable in water, air humidity, water steam and polar solvents.However, due to a higher covalency and a lower basicity, thesubstitutionally-incorporated divalent lead and/or divalent copper ionsin the host lattice of the chemical compound yields luminescentmaterials having improved resistance against water, air humidity andpolar solvents.

The divalent lead and/or divalent copper ions within the host lattice donot act as activators (also referred to herein as “luminescent ions”)and, therefore do not luminance. Rather, it has been found that theseions tend to influence the crystal field splitting as well as thecovalency of the chemical compound. As a result, the substitutionalincorporation of divalent lead and/or copper ions within the hostlattice tends to influence luminescent-optical properties of thechemical compounds so as to improve luminescent intensity and desirablyshift the emission maxima, color points, and shape of emission spectra.

It has been found that phosphors having chemical compounds that containsubstitutionally-incorporated divalent lead and/or divalent copper ionsshow improved emission intensities as compared with phosphors havingchemical compounds that do not contain substitutionally-incorporateddivalent lead and/or divalent copper ions.

In addition, it has been found that phosphors having chemical compoundsthat contain substitutionally-incorporated divalent lead and/or divalentcopper ions tend to show improved luminescent properties for excitationwavelength higher than about 360 nm. At excitation wavelengths higherthan about 360 nm, the divalent lead and/or divalent copper ions do notexhibit their own radiation transfers due to the energy levels of theirelectron configuration, so that any kind of exciting radiation cannot belost. Furthermore, by substitutionally incorporating divalent leadand/or divalent copper ions, the emission wavelength can be shifted tohigher or lower energies as desired.

Lead ions having an ionic radius of 119 pm can substitute the alkalineearth ions Ca having an ionic radius of 100 pm and Sr having an ionicradius of 118 pm very easily. The electro negativity of lead with 1.55is much higher than that of Ca (1.04) and Sr (0.99). The preparation ofsubstances containing lead is complicated due to the possibility of anoxidation of these ions in reducing atmospheres. For the preparation oflead-containing compounds, which need reducing atmosphere, specialpreparation processes are necessary.

The influence of substitutionally-incorporated divalent lead ions in thecrystal field on the shifting of emission characteristics depends uponthe substituted ions. When divalent lead ions substitute Sr or Ba inEu-activated aluminates and/or silicates, the emission maximum tends tobe shifted to longer wavelengths due to smaller ionic radii of Pb ascompared with the ionic radii of Ba and Sr. That leads to a strongercrystal field surrounding the activator ion.

A similar effect shows the substitution of divalent copper ions foralkaline earth ions. Here, an additional influence is effective. Due tothe higher ionic potential of copper as a quotient of ionic charge andionic radius compared to the bigger alkaline earth ions, the copper ionscan attract the neighboring oxygen ions stronger than the alkaline earthions. So the substitution of the bigger alkaline earth ions Ca, Sr andBa by copper leads to a stronger crystal field in the surrounding of theactivator ions, too. Thus, the shape of emission bands can beinfluenced, the shifting of the emission peak to longer wavelength isconnected in a broadening of the emission curves for band emission. Inaddition, it should be possible to increase the intensity of emission bysubstitution of ions copper and lead. Generally, the shifting ofemission peaks to longer or shorter wavelengths are desirable in thefield of LED lighting. Here, it is necessary to realize a fine tuning toget a special wavelength for desired color points as well as for betterbrightness of optical devices. By using cations, copper and lead, such afine tuning should be possible.

As described above, the luminescent material may include one or morechemical compounds such as, for example, aluminates, silicates,antimonates, germinates, germinate-silicates, and/or phosphates.Exemplary embodiments of these luminescent materials are described ingreater detail below.

EXAMPLE 1

Luminescent materials for ultraviolet light or visible light excitationcomprise lead- and/or copper-containing aluminates exemplarilycharacterized according to the formula as follows:a(M′O).b(M″₂O).c(M″X).d(Al₂O₃).e(M′″O).f(M″″₂O₃).g(M′″″_(o)O_(p)).h(M″″″_(x)O_(y))  (1)

wherein M′ may be Pb, Cu, and/or any combination thereof; M″ may be oneor more monovalent elements, for example, Li, Na, K, Rb, Cs, Au, Ag,and/or any combination thereof; M′″ may be one or more divalentelements, for example, Be, Mg, Ca, Sr, Ba, Zn, Cd, Mn, and/or anycombination thereof; M″″ may be one or more trivalent elements, forexample, Sc, B, Ga, In, and/or any combination thereof; M′″″ may be Si,Ge, Ti, Zr, Mn, V, Nb, Ta, W, Mo, and/or any combination thereof; M″″″may be Bi, Sn, Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho,Er, Tm, Yb, Lu, and/or any combination thereof; X may be F, Cl, Br, I,and/or any combination thereof; 0<a≦2; 0≦b≦2; 0≦c≦2; 0<d≦8; 0<e≦4;0≦f≦3; 0≦g≦8; 0<h≦2; 1≦o≦2; 1≦p≦5; 1≦x≦2; and 1≦y≦5.a(M′O).b(M″₂O).c(M″X).4-a-b-c(M′″O).7(Al₂O₃).d(B₂O₃).e(Ga₂O₃).f(SiO₂).g(GeO₂).h(M″″_(x)O_(y))  (2)

wherein M′ may be Pb, Cu, and/or any combination thereof; M″ may be oneor more monovalent elements, for example, Li, Na, K, Rb, Cs, Au, Ag,and/or any combination thereof, M′″ may be one or more divalentelements, for example, Be, Mg, Ca, Sr, Ba, Zn, Cd, Mn, and/or anycombination thereof; M″″ may be Bi, Sn, Sb, Sc, Y, La, In, Ce, Pr, Nd,Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and any combination thereof,X may be F, Cl, Br, I, and any combination thereof; 0<a≦4; 0≦b2; 0≦c≦2;0≦d≦1; 0≦e≦1; 0≦f≦1; 0≦g≦1; 0<h≦1; 1≦x≦2; and 1≦y≦5.

The preparation of copper- as well as lead-containing luminescentmaterials may be a basic solid state reaction. Pure starting materialswithout any impurities, e.g. iron, may be used. Any starting materialwhich may transfer into oxides via a heating process may be used to formoxygen dominated phosphors.

EXAMPLES OF PREPARATION Preparation of the Luminescent Material HavingFormula (3)

Cu_(0.02)Sr_(3.98)Al₁₄O₂₅:Eu  (3)

Starting materials: CuO, SrCO₃, Al(OH)₃, Eu₂O₃, and/or any combinationthereof.

The starting materials in the form of oxides, hydroxides, and/orcarbonates may be mixed in stoichiometric proportions together withsmall amounts of flux, e.g., H₃BO₃. The mixture may be fired in analumina crucible in a first step at about 1,200° C. for about one hour.After milling the pre-fired materials a second firing step at about1,450° C. in a reduced atmosphere for about 4 hours may be followed.After that the material may be milled, washed, dried and sieved. Theresulting luminescent material may have an emission maximum of about 494nm. TABLE 1 copper-containing Eu²⁺-activated aluminate compared withEu²⁺-activated aluminate without copper at about 400 nm excitationwavelength Compound Compound containing copper without copperCu_(0.02)Sr_(3.98)Al₁₄O₂₅:Eu Sr₄Al₁₄O₂₅:Eu Luminous density (%) 103.1100 Wavelength (nm) 494 493

Preparation of the luminescent material having formula (4)Pb_(0.05)Sr_(3.95)Al₁₄O₂₅:Eu  (4)

Starting materials: PbO, SrCO₃, Al₂O₃, EU₂O₃, and/or any combinationthereof.

The starting materials in form of very pure oxides, carbonates, or othercomponents which may decompose thermally into oxides, may be mixed instoichiometric proportion together with small amounts of flux, forexample, H₃BO₃. The mixture may be fired in an alumina crucible at about1,200° C. for about one hour in the air. After milling the pre-firedmaterials a second firing step at about 1,450° C. in air for about 2hours and in a reduced atmosphere for about 2 hours may be followed.Then the material may be milled, washed, dried, and sieved. Theresulting luminescent material may have an emission maximum of fromabout 494.5 nm n. TABLE 2 lead-containing Eu²⁺-activated aluminatecompared with Eu²⁺-activated aluminate without lead at about 400 nmexcitation wavelength Compound Lead-containing compound without leadPb_(0.05)Sr_(3.95)Al₁₄O₂₅:Eu Sr₄Al₁₄O₂₅:Eu Luminous density (%) 101.4100 Wavelength (nm) 494.5 493

TABLE 3 optical properties of some copper- and/or lead-containingaluminates excitable by long wave ultraviolet and/or by visible lightand their luminous density in % at 400 nm excitation wavelength Luminousdensity at 400 nm excitation Peak wave compared with length of lead-Possible compounds not and/or copper- Peak wave length of excitationcontaining containing materials without Composition range(nm)copper/lead (%) materials (nm) lead/copper (nm)Cu_(0.5)Sr_(3.5)Al₁₄O₂₅:Eu 360-430 101.2 495 493Cu_(0.02)Sr_(3.98)Al₁₄O₂₅:Eu 360-430 103.1 494 493Pb_(0.05)Sr_(3.95)Al₁₄O₂₅:Eu 360-430 101.4 494.5 493Cu_(0.01)Sr_(3.99)Al_(13.995)Si_(0.005)O₂₅:Eu 360-430 103 494 492Cu_(0.01)Sr_(3.395)Ba_(0.595)Al₁₄O₂₅:Eu, 360-430 100.8 494 493 DyPb_(0.05)Sr_(3.95)Al_(13.95)Ga_(0.05)O₂₅:Eu 360-430 101.5 494 494

EXAMPLE 2

Luminescent materials for ultraviolet light or visible light excitationcomprise lead- and/or copper-containing aluminates exemplarilycharacterized according to the formula as follows:a(M′O).b(M″O).c(Al₂O₃).d(M′″₂O₃).e(M″″O₂).f(M′″″_(x)O_(y))  (5)

wherein M′ may be Pb, Cu, and/or any combination thereof; M″ may be Be,Mg, Ca, Sr, Ba, Zn, Cd, Mn, and/or any combination thereof; M′″ may beB, Ga, In, and/or any combination thereof; M′″″ may be Si, Ge, Ti, Zr,Hf, and/or any combination thereof; M′″″ may be Bi, Sn, Sb, Sc, Y, La,Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and/or anycombination thereof; 0<a≦1; 0≦b≦2; 0<c≦8; 0≦d≦1; 0≦e≦1; 0<f≦; 1≦x≦2; and1≦y≦5.

The luminous peak and density of Example 2 are described in Table 7,which will be shown below.

EXAMPLE OF PREPARATION Preparation of the Luminescent Material HavingFormula (6)

Cu_(0.05)Sr_(0.95)Al_(1.9997)Si_(0.0003)O₄:Eu  (6)

Starting materials: CuO, SrCO₃, Al₂O₃, SiO₂, Eu₂O₃, and/or anycombination thereof.

The starting materials in the form of, for example, pure oxides and/oras carbonates may be mixed in stoichiometric proportions together withsmall amounts of flux, for example, AlF₃. The mixture may be fired in analumina crucible at about 1,250° C. in a reduced atmosphere for about 3hours. After that the material may be milled, washed, dried and sieved.The resulting luminescent material may have an emission maximum of about521.5 nm. TABLE 4 copper-containing Eu²⁺-activated aluminate comparedwith Eu²⁺-activated aluminate without copper at about 400 nm excitationwavelength Compound Compound containing copper without copperCu_(0.05)Sr_(0.95)Al_(1.9997)Si_(0.0003)O₄:Eu SrAl₂O₄:Eu Luminousdensity (%) 106 100 Wavelength (nm) 521.5 519

Preparation of the luminescent material having formula (7)Cu_(0.12)BaMg_(1.88)Al₁₆O₂₇:Eu  (7)

Starting materials: CuO, MgO, BaCO₃, Al(OH)₃, Eu₂O₃, and/or anycombination thereof.

The starting materials in the form of, for example, pure oxides,hydroxides, and/or carbonates may be mixed in stoichiometric proportionstogether with small amounts of flux, for example, AlF₃. The mixture maybe fired in an alumina crucible at about 1,420° C. in a reducedatmosphere for about 2 hours. After that the material may be milled,washed, dried, and sieved. The resulting luminescent material may havean emission maximum of about 452 nm. TABLE 5 copper-containingEu²⁺-activated aluminate compared with copper not doped Eu²⁺-activatedaluminate at 400 nm excitation wavelength Compound Comparison containingcopper without copper Cu_(0.12)BaMg_(1.88)Al₁₆O₂₇:Eu BaMg₂Al₁₆O₂₇:EuLuminous density (%) 101 100 Wavelength (nm) 452 450

Preparation of the luminescent material having formula (8)Pb_(0.1)Sr_(0.9)Al₂O₄:Eu  (8)

Starting materials: PbO, SrCO₃, Al(OH)₃, Eu₂O₃, and/or any combinationthereof.

The starting materials in form of, for example, pure oxides, hydroxides,and/or carbonates may be mixed in stoichiometric proportions togetherwith small amounts of flux, for example, H₃BO₃. The mixture may be firedin an alumina crucible at about 1,000° C. for about 2 hours in the air.After milling the pre-fired materials a second firing step at about1,420° C. in the air for about 1 hour and in a reduced atmosphere forabout 2 hours may be followed. After that the material may be milled,washed, dried and sieved. The resulting luminescent material may have anemission maximum of about 521 nm. TABLE 6 lead-containing Eu²⁺-activatedaluminate compared with Eu²⁺-activated aluminate without lead at about400 nm excitation wavelength Compound Lead-containing compound withoutlead Pb_(0.1)Sr_(0.9)Al₂O₄:Eu SrAl₂O₄:Eu Luminous density (%) 102 100Wavelength (nm) 521 519

Results obtained in regard to copper- and/or lead-containing aluminatesare shown in table 7. TABLE 7 optical properties of some copper- and/orlead-containing aluminates excitable by long wave ultraviolet and/or byvisible light and their luminous density in % at 400 nm excitationwavelength Peak wave Luminous density at length of lead- Possible 400 nmexcitation and/or excitation compared with copper- Peak wave length ofrange copper/lead not doped containing materials without Composition(nm) compounds (%) materials (nm) lead/copper (nm)Cu_(0.05)Sr_(0.95)Al_(1.9997)Si_(0.0003)O₄:Eu 360-440 106 521.5 519Cu_(0.2)Mg_(0.7995)Li_(0.0005)Al_(1.9)Ga_(0.1)O₄:Eu, 360-440 101.2 482480 Dy Pb_(0.1)Sr_(0.9)Al₂O₄:Eu 360-440 102 521 519Cu_(0.05)BaMg_(1.95)Al₁₆O₂₇:Eu, Mn 360-400 100.5 451, 515 450, 515Cu_(0.12)BaMg_(1.88)Al₁₆O₂₇:Eu 360-400 101 452 450Cu_(0.01)BaMg_(0.99)Al₁₀O₁₇:Eu 360-400 102.5 451 449Pb_(0.1)BaMg_(0.9)Al_(9.5)Ga_(0.5)O₁₇:Eu, 360-400 100.8 448 450 DyPb_(0.08)Sr_(0.902)Al₂O₄:Eu, Dy 360-440 102.4 521 519Pb_(0.2)Sr_(0.8)Al₂O₄:Mn 360-440 100.8 658 655Cu_(0.06)Sr_(0.94)Al₂O₄:Eu 360-440 102.3 521 519Cu_(0.05)Ba_(0.94)Pb_(0.06)Mg_(0.95)Al₁₀O₁₇:Eu 360-440 100.4 451 449Pb_(0.3)Ba_(0.7)Cu_(0.1)Mg_(1.9)Al₁₆O₂₇:Eu 360-400 100.8 452 450Pb_(0.3)Ba_(0.7)Cu_(0.1)Mg_(1.9)Al₁₆O₂₇:Eu, 360-400 100.4 452, 515 450,515 Mn

EXAMPLE 3

Luminescent materials for ultraviolet light or visible light excitationcomprise lead- and/or copper-containing silicates exemplarilycharacterized according to the formula as follows:a(M′O).b(M″O).c(M′″X).d(M′″₂O).e(M″″₂O₃).f(M′″″_(o)O_(p)).g(SiO₂).h(M″″″_(x)O_(y))  (9)

wherein M′ may be Pb, Cu, and/or any combination thereof; M″ may be Be,Mg, Ca, Sr, Ba, Zn, Cd, Mn, and/or any combination thereof; M″″ may beLi, Na, K, Rb, Cs, Au, Ag, and/or any combination thereof; M″″ may beAl, Ga, In, and/or any combination thereof; M′″″ may be Ge, V, Nb, Ta,W, Mo, Ti, Zr, Hf, and/or any combination thereof; M″″″ may be Bi, Sn,Sb, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu,and/or any combination thereof; X may be F, Cl, Br, I, and anycombination thereof; 0<a≦2; 0<b≦8; 0≦c≦4; 0≦d≦2; 0≦e≦2; 0≦f≦2; 0<g≦10;0<h≦5; 1≦o≦2; 1≦p≦5; 1≦x≦2; and 1≦y≦5.

The copper-containing silicates exemplarily described herein may, insome embodiments, contain SiO₄ and be characterized as having an Olivinstructure (orthorhombic) or β-K₂SO₄ structure (orthorhombic); containSi₂O₈ and be characterized as having a trigonal Glaserite (K₃Na(SO₄)₂)or monoclinic Merwinite structure; contain Si₂O₇ and be characterized ashaving a tetragonal Ackermanite structure; contain SiO₅ and becharacterized as having a tetragonal structure; and/or contain Si₂O₅ andbe characterized as having an orthorhombic structure.

The superior luminous density of Example 3 can be seen below.

EXAMPLE OF PREPARATION Preparation of the Luminescent Material HavingFormula (10)

Cu_(0.05)Sr_(1.7)Ca_(0.25)SiO₄:Eu  (10)

Starting materials: CuO, SrCO₃, CaCO₃, SiO₂, Eu₂O₃, and/or anycombination thereof.

The starting materials in the form of pure oxides and/or carbonates maybe mixed in stoichiometric proportions together with small amounts offlux, for example, NH₄Cl. The mixture may be fired in an aluminacrucible at about 1,200° C. in an inert gas atmosphere (e.g., N₂ ornoble gas) for about 2 hours. Then the material may be milled. Afterthat, the material may be fired in an alumina crucible at about 1,200°C. in a slightly reduced atmosphere for about 2 hours. Then, thematerial may be milled, washed, dried, and sieved. The resultingluminescent material may have an emission maximum at about 592 nm. TABLE8 copper-containing Eu²⁺-activated silicate compared with Eu²⁺-activatedsilicate without copper at about 400 nm excitation wavelengthCopper-containing Compound compound without copperCu_(0.05)Sr_(1.7)Ca_(0.25)SiO₄:Eu Sr_(1.7)Ca_(0.3)SiO₄:Eu Luminousdensity (%) 104 100 Wavelength (nm) 592 588

Preparation of the Luminescent Material Having Formula (11):Cu_(0.2)Ba₂Zn_(0.2)Mg_(0.6)Si₂O₇:Eu  (11)

Starting materials: CuO, BaCO₃, ZnO, MgO, SiO₂, EU₂O₃, and/or anycombination thereof.

The starting materials in the form of very pure oxides and carbonatesmay be mixed in stoichiometric proportions together with small amountsof flux, for example, NH₄Cl. In a first step the mixture may be fired inan alumina crucible at about 1,100° C. in a reduced atmosphere for about2 hours. Then the material may be milled. After that the material may befired in an alumina crucible at about 1,235° C. in a reduced atmospherefor about 2 hours. Then that the material may be milled, washed, driedand sieved. The resulting luminescent material may have an emissionmaximum at about 467 nm. TABLE 9 copper-containing Eu²⁺-activatedsilicate compared with Eu²⁺-activated silicate without copper at 400 nmexcitation wavelength Compound Copper-containing compound without copperCu_(0.2)Sr₂Zn_(0.2)Mg_(0.6)Si₂O₇:Eu Sr₂Zn₂Mg_(0.6)Si₂O₇:Eu Luminousdensity 101.5 100 (%) Wavelength (nm) 467 465

Preparation of the luminescent material having formula (12)Pb_(0.1)Ba_(0.95)Sr_(0.95)Si_(0.998)Ge_(0.002)O₄:Eu  (12)

Starting materials: PbO, SrCO₃, BaCO₃, SiO₂, GeO₂, Eu₂O₃, and/or anycombination thereof.

The starting materials in the form of oxides and/or carbonates may bemixed in stoichiometric proportions together with small amounts of flux,for example, NH₄Cl. The mixture may be fired in an alumina crucible atabout 1,000° C. for about 2 hours in the air. After milling thepre-fired materials a second firing step at 1,220° C. in air for 4 hoursand in reducing atmosphere for 2 hours may be followed. After that thematerial may be milled, washed, dried and sieved. The resultingluminescent material may have an emission maximum at about 527 nm. TABLE10 lead-containing Eu²⁺-activated silicate compared with Eu²⁺-activatedsilicate without lead at about 400 nm excitation wavelength CompoundLead-containing compound without leadPb_(0.1)Ba_(0.95)Sr_(0.95)Si_(0.998)Ge_(0.002)O₄:Eu BaSrSiO₄:Eu Luminousdensity 101.3 100 (%) Wavelength (nm) 527 525

Preparation of the luminescent material having formula (13)Pb_(0.25)Sr_(3.75)Si₃O₈Cl₄:Eu  (13)

Starting materials: PbO, SrCO₃, SrCl₂, SiO₂, Eu₂O₃, and any combinationthereof.

The starting materials in the form of oxides, chlorides, and/orcarbonates may be mixed in stoichiometric proportions together withsmall amounts of flux, for example, NH₄Cl. The mixture may be fired inan alumina crucible in a first step at about 1,100° C. for about 2 hoursin the air. After milling the pre-fired materials a second firing stepat about 1,220° C. in the air for about 4 hours and in a reducedatmosphere for about 1 hour may be followed. After that the material maybe milled, washed, dried and sieved. The resulting luminescent materialmay have an emission maximum at about 492 nm. TABLE 11 lead-containingEu²⁺-activated chlorosilicate compared with Eu²⁺-activatedchlorosilicate without lead at 400 nm excitation wavelength CompoundLead-containing compound without lead Pb_(0.25)Sr_(3.75)Si₃O₈Cl₄:EuSr₄Si₃O₈Cl₄:Eu Luminous density (%) 100.6 100 Wavelength (nm) 492 490

Results obtained with respect to copper- and/or lead-containingsilicates are shown in table 12. TABLE 12 optical properties of somecopper- and/or lead-containing rare earth activated silicates excitableby long wave ultraviolet and/or by visible light and their luminousdensity in % at about 400 nm excitation wavelength Luminous density atPeak wave length Possible 400 nm excitation of lead- and/or Peak wavelength excitation compared with copper- of materials range copper/leadnot doped containing without Composition (nm) compounds (%) materials(nm) lead/copper (nm)Pb_(0.1)Ba_(0.95)Sr_(0.95)Si_(0.998)Ge_(0.002)O₄:Eu 360-470 101.3 527525 Cu_(0.02)(Ba,Sr,Ca,Zn)_(1.98)SiO₄:Eu 360-500 108.2 565 560Cu_(0.05)Sr_(1.7)Ca_(0.25)SiO₄:Eu 360-470 104 592 588Cu_(0.05)Li_(0.002)Sr_(1.5)Ba_(0.448)SiO₄:Gd, 360-470 102.5 557 555 EuCu_(0.2)Sr₂Zn_(0.2)Mg_(0.6)Si₂O₇:Eu 360-450 101.5 467 465Cu_(0.02)Ba_(2.8)Sr_(0.2)Mg_(0.98)Si₂O₈:Eu, 360-420 100.8 440, 660 438,660 Mn Pb_(0.25)Sr_(3.75)Si₃O₈Cl₄:Eu 360-470 100.6 492 490Cu_(0.2)Ba_(2.2)Sr_(0.75)Pb_(0.05)Zn_(0.8)Si₂O₈:Eu 360-430 100.8 448 445Cu_(0.2)Ba₃Mg_(0.8)Si_(1.99)Ge_(0.01)O₈:Eu 360-430 101 444 440Cu_(0.5)Zn_(0.5)Ba₂Ge_(0.2)Si_(1.8)O₇:Eu 360-420 102.5 435 433Cu_(0.8)Mg_(0.2)Ba₃Si₂O₈:Eu, Mn 360-430 103 438, 670 435, 670Pb_(0.15)Ba_(1.84)Zu_(0.01)Si_(0.99)Zr_(0.01)O₄:Eu 360-500 101 512 510Cu_(0.2)Ba₅Ca_(2.8)Si₄O₁₆:Eu 360-470 101.8 495 491

EXAMPLE 4

Luminescent materials for ultraviolet light or visible light excitationcomprise lead- and/or copper-containing antimonates exemplarilycharacterized according to the formula as follows:a(M′O).b(M″₂O).c(M″X).d(Sb₂O₅).e(M′″O).f(M″″_(x)O_(y))  (14)

wherein M′ may be Pb, Cu, and/or any combination thereof; M″ may be Li,Na, K, Rb, Cs, Au, Ag, and/or any combination thereof; M′″ may be Be,Mg, Ca, Sr, Ba, Zn, Cd, Mn, and/or any combination thereof; M″″ may beBi, Sn, Sc, Y, La, Pr, Sm, Eu, Tb, Dy, Gd, and/or any combinationthereof; X may be F, Cl, Br, I, and/or any combination thereof; 0<a≦2;0≦b≦2; 0≦c≦4; 0<d≦8; 0≦e≦8; 0≦f≦2; 1≦x≦2; and 1≦y≦5.

EXAMPLES OF PREPARATION Preparation of the Luminescent Material HavingFormula (15)

Cu_(0.2)Mg_(1.7)Li_(0.2)Sb₂O₇:Mn  (15)

Starting materials: CuO, MgO, Li₂O, Sb₂O₅, MnCO₃, and/or any combinationthereof.

The starting materials in the form of oxides may be mixed instoichiometric proportion together with small amounts of flux. In afirst step the mixture may be fired in an alumina crucible at about 985°C. in the air for about 2 hours. After pre-firing the material may bemilled again. In a second step the mixture may be fired in an aluminacrucible at about 1,200° C. in an atmosphere containing oxygen for about8 hours. After that the material may be milled, washed, dried andsieved. The resulting luminescent material may have an emission maximumat about 626 nm. TABLE 13 copper-containing antimonate compared withantimonate without copper at about 400 nm excitation wavelengthCopper-containing Comparison compound without copperCu_(0.2)Mg_(1.7)Li_(0.2)Sb₂O₇:Mn Mg₂Li_(0.2)Sb₂O₇:Mn Luminous density(%) 101.8 100 Wavelength (nm) 652 650

Preparation of the luminescent material having formula (16)Pb_(0.006)Ca_(0.6)Sr_(0.394)Sb₂O₆  (16)

Starting materials: PbO, CaCO₃, SrCO₃, Sb₂O₅, and/or any combinationthereof.

The starting materials in the form of oxides and/or carbonates may bemixed in stoichiometric proportions together with small amounts of flux.In a first step the mixture may be fired in an alumina crucible at about975° C. in the air for about 2 hours. After pre-firing the material maybe milled again. In a second step the mixture may be fired in an aluminacrucible at about 1,175° C. in the air for about 4 hours and then in anoxygen-containing atmosphere for about 4 hours. After that the materialmay be milled, washed, dried and sieved. The resulting luminescentmaterial may have an emission maximum at about 637 nm. TABLE 14lead-containing antimonate compared with antimonate without lead at 400nm excitation wavelength Lead-containing Compound compound without leadPb_(0.006)Ca_(0.6)Sr_(0.394)Sb₂O₆ Ca_(0.6)Sr_(0.4)Sb₂O₆ Luminous density(%) 102 100 Wavelength (nm) 637 638

Results obtained in respect to copper- and/or lead-containingantimonates are shown in table 15. TABLE 15 optical properties of somecopper- and/or lead-containing antimonates excitable by long waveultraviolet and/or by visible light and their luminous density in % atabout 400 nm excitation wavelength Luminous density at Peak wave 400 nmexcitation length of lead- Peak wave length Possible compared withand/or copper- of materials excitation copper/lead not doped containingwithout Composition range (nm) compounds (%) materials (nm) lead/copper(nm) Pb_(0.2)Mg_(0.002)Ca_(1.798)Sb₂O₆F₂:Mn 360-400 102 645 649Cu_(0.15)Ca_(1.845)Sr_(0.005)Sb_(1.998)Si_(0.002)O₇:Mn 360-400 101.5 660658 Cu_(0.2)Mg_(1.7)Li_(0.2)Sb₂O₇:Mn 360-400 101.8 652 650Cu_(0.2)Pb_(0.01)Ca_(0.79)Sb_(1.98)Nb_(0.02)O₆:Mn 360-400 98.5 658 658Cu_(0.01)Ca_(1.99)Sb_(1.9995)V_(0.0005)O₇:Mn 360-400 100.5 660 657Pb_(0.006)Ca_(0.6)Sr_(0.394)Sb₂O₆ 360-400 102 637 638Cu_(0.02)Ca_(0.9)Sr_(0.5)Ba_(0.4)Mg_(0.18)Sb₂O₇ 360-400 102.5 649 645Pb_(0.198)Mg_(0.004)Ca_(1.798)Sb₂O₆F₂ 360-400 101.8 628 630

EXAMPLE 5

Luminescent materials for ultraviolet light or visible light excitationcomprise lead- and/or copper-containing germinates and/or agerminate-silicates exemplarily characterized according to the formulaas follows:a(M′O).b(M″₂O).c(M″X).d(GeO₂).e(M′″O).f(M″″₂O₃).g(M′″″_(o)O_(p)).h(M″″″_(x)O_(y))  (17)

wherein M′ may be Pb, Cu, and/or any combination thereof; M″ may be Li,Na, K, Rb, Cs, Au, Ag, and/or any combination thereof; M′″ may be Be,Mg, Ca, Sr, Ba, Zn, Cd, and/or any combination thereof; M″″ may be Sc,Y, B, Al, La, Ga, In, and/or any combination thereof; M′″″ may be Si,Ti, Zr, Mn, V, Nb, Ta, W, Mo, and/or any combination thereof; M″″″ maybe Bi, Sn, Pr, Sm, Eu, Gd, Dy, and/or any combination thereof; X may beF, Cl, Br, I, and/or any combination thereof; 0<a≦2; 0≦b≦2; 0≦c≦10;0<d≦10; 0≦e≦14; 0≦f≦14; 0≦g≦10; 0≦h≦2; 1≦o≦2; 1≦p≦5; 1≦x≦2; and 1≦y≦5.

EXAMPLE OF PREPARATION Preparation of the Luminescent Material HavingFormula (18)

Pb_(0.004)Ca_(1.99)Zn_(0.006)Ge_(0.8)Si_(0.2)O₄:Mn  (18)

Starting materials: PbO, CaCO₃, ZnO, GeO₂, SiO₂, MnCO₃, and/or anycombination thereof,

The starting materials in the form of oxides and/or carbonates may bemixed in stoichiometric proportions together with small amounts of flux,for example, NH₄Cl. In a first step the mixture may be fired in analumina crucible at about 1,200° C. in an oxygen-containing atmospherefor about 2 hours. Then, the material may be milled again. In a secondstep the mixture may be fired in an alumina crucible at about 1,200° C.in oxygen containing atmosphere for about 2 hours. After that thematerial may be milled, washed, dried and sieved. The resultingluminescent material may have an emission maximum at about 655 nm. TABLE16 lead-containing Mn-activated germanate compared with Mn-activatedgermanate without lead at about 400 nm excitation wavelengthCopper-containing compound Comparison without copperPb_(0.004)Ca_(1.99)Zn_(0.006)Ge_(0.8)Si_(0.2)O₄:MnCa_(1.99)Zn_(0.01)Ge_(0.8)Si_(0.2)O₄:Mn Luminous density (%) 101.5 100Wavelength (nm) 655 657

Preparation of the luminescent material having formula (19)Cu_(0.46)Sr_(0.54)Ge_(0.6)Si_(0.4)O₃:Mn  (19)

Starting materials: CuO, SrCO₃, GeO₂, SiO₂, MnCO₃, and/or anycombination thereof.

The starting materials in the form of oxides and/or carbonates may bemixed in stoichiometric proportions together with small amounts of flux,for example, NH₄Cl. In a first step the mixture may be fired in analumina crucible at about 1,100° C. in an oxygen-containing atmospherefor about 2 hours. Then, the material may be milled again. In a secondstep the mixture may be fired in an alumina crucible at about 1,180° C.in an oxygen-containing atmosphere for about 4 hours. After that thematerial may be milled, washed, dried and sieved. The resultingluminescent material may have an emission maximum at about 658 nm. TABLE17 copper-containing Mn-activated germanate-silicate compared withMn-activated germanate-silicate without copper at 400 nm excitationwavelength Copper-containing Compound compound without copperCu_(0.46)Sr_(0.54)Ge_(0.6)Si_(0.4)O₃:Mn SrGe_(0.6)Si_(0.4)O₃:Mn Luminousdensity (%) 103 100 Wavelength (nm) 658 655

TABLE 18 optical properties of some copper- and/or lead-containinggermanate- silicates excitable by long wave ultraviolet and/or byvisible light and their luminous density in % at about 400 nm excitationwavelength Peak wave Luminous density at length of Peak wave Possible400 nm excitation lead- and/or length of excitation compared withcopper- materials without range copper/lead not doped containinglead/copper Composition (nm) compounds (%) materials (nm) (nm)Pb_(0.004)Ca_(1.99)Zn_(0.006)Ge_(0.8)Si_(0.2)O₄:Mn 360-400 101.5 655 657Pb_(0.002)Sr_(0.954)Ca_(1.044)Ge_(0.93)Si_(0.07)O₄:Mn 360-400 101.5 660661 Cu_(0.46)Sr_(0.54)Ge_(0.6)Si_(0.4)O₃:Mn 360-400 103 658 655Cu_(0.002)Sr_(0.998)Ba_(0.99)Ca_(0.01)Si_(0.98)Ge_(0.02)O₄:Eu 360-470102 538 533 Cu_(1.45)Mg_(26.55)Ge_(9.4)Si_(0.6)O₄₈:Mn 360-400 102 660657 Cu_(1.2)Mg_(26.8)Ge_(8.9)Si_(1.1)O₄₈:Mn 360-400 103.8 670 656Cu₄Mg₂₀Zn₄Ge₅Si_(2.5)O₃₈F₁₀:Mn 360-400 101.5 658 655Pb_(0.001)Ba_(0.849)Zn_(0.05)Sr_(1.1)Ge_(0.04)Si_(0.96)O₄:Eu 360-470101.8 550 545 Cu_(0.05)Mg_(4.95)GeO₆F₂:Mn 360-400 100.5 655 653Cu_(0.05)Mg_(3.95)GeO_(5.5)F:Mn 360-400 100.8 657 653

EXAMPLE 6

Luminescent materials for ultraviolet light or visible light excitationcomprise lead- and/or copper-containing phosphates exemplarilycharacterized according to the formula as follows:a(M′O).b(M″₂O).c(M″X).d(P₂O₅).e(M′″O).f(M″″₂O₃).g(M′″″O₂).h(M″″″_(x)O_(y))  (20)

wherein M′ may be Pb, Cu, and/or any combination thereof; M″ may be Li,Na, K, Rb, Cs, Au, Ag, and/or any combination thereof; M′″ may be Be,Mg, Ca, Sr, Ba, Zn, Cd, Mn, and/or any combination thereof; M″″ may beSc, Y, B, Al, La, Ga, In, and/or any combination thereof; M′″″ may beSi, Ge, Ti, Zr, Hf, V, Nb, Ta, W, Mo, and/or any combination thereof;M″″″ may be Bi, Sn, Pr, Sm, Eu, Gd, Dy, Ce, Tb, and/or any combinationthereof; X may be F, Cl, Br, I, and/or any combination thereof; 0<a≦2;0≦b≦12; 0≦c≦16; 0≦d≦3; 0≦e≦5; 0≦f≦3; 0≦g≦2; 0<h≦2; 1≦x≦2; and 1≦y≦5.

The luminescent materials comprising the lead- and/or copper-containingphosphates may be used as compounds for ultraviolet light in a lightemitting device.

EXAMPLES OF PREPARATION Preparation of the Luminescent Material HavingFormula (21)

Cu_(0.02)Ca_(4.98)(PO₄)₃Cl:Eu  (21)

Starting materials: CuO, CaCO₃, Ca₃(PO₄)₂, CaCl₂, Eu₂O₃, and/or anycombination thereof,

The starting materials in the form of oxides, phosphates, and/orcarbonates and chlorides may be mixed in stoichiometric proportionstogether with small amounts of flux. The mixture may be fired in analumina crucible at about 1,240° C. in reducing atmosphere for about 2hours. After that the material may be milled, washed, dried and sieved.The luminescent material may have an emission maximum at about 450 nm.TABLE 19 copper-containing Eu²⁺-activated chlorophosphate compared withEu²⁺-activated chlorophosphate without copper at about 400 nm excitationwavelength Copper-containing Compound compound without copperCu_(0.02)Ca_(4.98)(PO₄)₃Cl:Eu Ca₅(PO₄)₃Cl:Eu Luminous density (%) 101.5100 Wavelength (nm) 450 447

TABLE 20 copper- and/or lead-containing phosphates excitable by longwave ultraviolet and/or by visible light and their luminous density in %at about 400 nm excitation wavelength Peak wave length Luminous densityat 400 nm of lead- and/or Peak wave length Possible excitation comparedcopper- of materials excitation with copper/lead not containing withoutComposition range (nm) doped compounds (%) materials (nm) lead/copper(nm) Cu_(0.02)Sr_(4.98)(PO₄)₃Cl:Eu 360-410 101.5 450 447Cu_(0.2)Mg_(0.8)BaP₂O₇:Eu, Mn 360-400 102 638 635Pb_(0.5)Sr_(1.5)P_(1.84)B_(0.16)O_(6.84):Eu 360-400 102 425 420Cu_(0.5)Mg_(0.5)Ba₂(P, Si)₂O₈:Eu 360-400 101 573 570 Cu_(0.5)Sr_(9.5)(P,B)₆O₂₄Cl₂:Eu 360-410 102 460 456 Cu_(0.5)Ba₃Sr_(6.5)P₆O₂₄(F,Cl)₂:Eu360-410 102 443 442 Cu_(0.05)(Ca,Sr,Ba)_(4.95)P₃O₁₂Cl:Eu,Mn 360-410101.5 438, 641 435, 640 Pb_(0.1)Ba_(2.9)P₂O₈:Eu 360-400 103 421 419

The lead- and/or copper-containing luminescent materials exemplarilydescribed above can act as converter for light emitting devices, such asultraviolet as well as blue emitting LEDs, back lights and paintingpigments. They can convert the excitation wavelength from theultraviolet and blue light to longer visible wavelength. According tosome embodiments, one or more of the lead- and/or copper-containingluminescent materials exemplarily described above may be used or mixedto produce a luminescent material with a color temperature ranging fromabout 2,000K to about 8,000K or about 10,000K and superior colorrendering index of greater than about 60 (e.g., between about 60 andabout 90, or greater than about 90, or between about 90 and about 95).Thus, for all color temperatures as well as for all color coordinatesinside of the white light coordinates, an appropriate luminescentmaterial or mixture thereof can be found.

1. A luminescent material for a light emitting diode (LED), comprising:a first compound including a host lattice and a luminescent ion withinthe host lattice, wherein the host lattice comprises first ions andoxygen, wherein a first portion of the first ions is substituted bydivalent copper ions, wherein the first compound emits light uponexcitation with ultraviolet light or visible light emitted by the LED,and wherein the first compound has an Olivin crystal structure, aβ-K₂SO₄ crystal structure, a trigonal Glaserite (K₃Na(SO₄)₂) ormonoclinic Merwinite crystal structure, a tetragonal Ackermanite crystalstructure, a tetragonal crystal structure or an orthorhombic crystalstructure.
 2. The luminescent material of claim 1, wherein theluminescent material has a color temperature ranging from about 2,000Kto about 8,000K.
 3. The luminescent material of claim 1, wherein theluminescent material has a color temperature of about 10,000K.
 4. Theluminescent material of claim 1, wherein the luminescent material has acolor rendering index greater than about
 60. 5. The luminescent materialof claim 4, wherein the luminescent material has a color rendering indexbetween about 60 and about
 90. 6. The luminescent material of claim 4,wherein the luminescent material has a color rendering index greaterthan about
 90. 7. The luminescent material of claim 1, wherein the firstions comprise at least one of Be, Mg, Ca, Sr, Ba, Zn, Cd and Mn.
 8. Theluminescent material of claim 1, wherein the luminescent ion comprisesat least one of Bi, Sn, Sb, Sc, Y, La, In, Ce, Pr, Nd, Pm, Sm, Eu, Gd,Tb, Dy, Ho, Er, Tm, Yb and Lu.
 9. The luminescent material of claim 1,wherein the first compound comprises a silicate.
 10. The luminescentmaterial of claim 9, wherein the first compound comprises Ge.
 11. Theluminescent material of claim 1, further comprising at least one secondcompound selected from the group consisting of an aluminate, a silicate,an antimonate, a germinate, a germinate-silicate and a phosphate. 12.The luminescent material of claim 1, wherein the first compound emitswhite light upon excitation with ultraviolet light or visible light. 13.A luminescent material for a light emitting diode (LED), comprising: acompound including a host lattice and a luminescent ion within the hostlattice, wherein the host lattice comprises first ions and oxygen,wherein a first portion of the first ions is substituted by copper ions,wherein the compound emits light upon excitation with ultraviolet lightor visible light emitted by the LED, and wherein the copper ions do actas luminescent ions upon excitation with the ultraviolet light orvisible light.